In House, M.D., James Wilson serves as the hospital’s oncologist and House’s closest friend.
Robert Sean Leonard plays Wilson, who leads the Department of Oncology at Princeton-Plainsboro. His specialty places him in frequent contact with patients facing cancer, while his friendship with House gives him a perspective different from that of House’s diagnostic colleagues.
Wilson often acts as House’s moral counterweight. He challenges House’s decisions, helps interpret his behavior, and remains involved despite House’s manipulation and self-destructive habits. Their friendship is one of the show’s most persistent relationships.
Wilson’s personal life also drives several storylines, including his marriages and his relationships with patients. The character’s surname is Wilson, while his full name is James Evan Wilson. The distinction matters because the series commonly refers to him simply as Wilson.